Hund?s Rule and Metallic Ferromagnetism
Abstract
We study tightbinding models of itinerant electrons in two different bands, with effective onsite interactions expressing Coulomb repulsion and Hund's rule. We prove that, for sufficiently large onsite exchange anisotropy, all ground states show metallic ferromagnetism: They exhibit a macroscopic magnetization, a macroscopic fraction of the electrons is spatially delocalized, and there is no energy gap for kinetic excitations.
 Publication:

Journal of Statistical Physics
 Pub Date:
 March 2005
 DOI:
 10.1007/s109550042174y
 arXiv:
 arXiv:condmat/0404483
 Bibcode:
 2005JSP...118..973F
 Keywords:

 Metallic Ferromagnetism;
 Hund's rule;
 twoband tightbinding models;
 Condensed Matter  Strongly Correlated Electrons;
 Condensed Matter  Statistical Mechanics;
 Mathematical Physics;
 Mathematics  Mathematical Physics
 EPrint:
 17 pages